LibJS: Boolean, Number and String prototypes should have values too

It appears that calling .valueOf() on an objectified primitive's
prototype should return a value after all.

This matches what other engines are doing.

Libraries/LibJS/Runtime/BooleanObject.cpp

@@ -28,6 +28,7 @@
 #include <LibJS/Runtime/BooleanObject.h>
 
 namespace JS {
+
 BooleanObject::BooleanObject(bool value)
     : m_value(value)
 {
@@ -37,4 +38,5 @@ BooleanObject::BooleanObject(bool value)
 BooleanObject::~BooleanObject()
 {
 }
+
 }

Libraries/LibJS/Runtime/BooleanPrototype.cpp

@@ -26,14 +26,15 @@
 
 #include <AK/Function.h>
 #include <LibJS/Interpreter.h>
-#include <LibJS/Runtime/BooleanObject.h>
 #include <LibJS/Runtime/BooleanPrototype.h>
 #include <LibJS/Runtime/Error.h>
 
 namespace JS {
 
 BooleanPrototype::BooleanPrototype()
+    : BooleanObject(false)
 {
+    set_prototype(interpreter().object_prototype());
     put_native_function("toString", to_string);
     put_native_function("valueOf", value_of);
 }

Libraries/LibJS/Runtime/BooleanPrototype.h

@@ -26,11 +26,11 @@
 
 #pragma once
 
-#include <LibJS/Runtime/Object.h>
+#include <LibJS/Runtime/BooleanObject.h>
 
 namespace JS {
 
-class BooleanPrototype final : public Object {
+class BooleanPrototype final : public BooleanObject {
 public:
     BooleanPrototype();
     virtual ~BooleanPrototype() override;

Libraries/LibJS/Runtime/NumberObject.h

@@ -30,7 +30,7 @@
 
 namespace JS {
 
-class NumberObject final : public Object {
+class NumberObject : public Object {
 public:
     explicit NumberObject(double);
     virtual ~NumberObject() override;

Libraries/LibJS/Runtime/NumberPrototype.cpp

@@ -24,12 +24,15 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+#include <LibJS/Interpreter.h>
 #include <LibJS/Runtime/NumberPrototype.h>
 
 namespace JS {
 
 NumberPrototype::NumberPrototype()
+    : NumberObject(0)
 {
+    set_prototype(interpreter().object_prototype());
 }
 
 NumberPrototype::~NumberPrototype()

Libraries/LibJS/Runtime/NumberPrototype.h

@@ -26,11 +26,11 @@
 
 #pragma once
 
-#include <LibJS/Runtime/Object.h>
+#include <LibJS/Runtime/NumberObject.h>
 
 namespace JS {
 
-class NumberPrototype final : public Object {
+class NumberPrototype final : public NumberObject {
 public:
     NumberPrototype();
     virtual ~NumberPrototype() override;

Libraries/LibJS/Runtime/StringObject.h

@@ -30,7 +30,7 @@
 
 namespace JS {
 
-class StringObject final : public Object {
+class StringObject : public Object {
 public:
     explicit StringObject(PrimitiveString*);
     virtual ~StringObject() override;

Libraries/LibJS/Runtime/StringPrototype.cpp

@@ -38,7 +38,9 @@
 namespace JS {
 
 StringPrototype::StringPrototype()
+    : StringObject(js_string(interpreter(), String::empty()))
 {
+    set_prototype(interpreter().object_prototype());
     put_native_property("length", length_getter, nullptr);
     put_native_function("charAt", char_at, 1);
     put_native_function("repeat", repeat, 1);

Libraries/LibJS/Runtime/StringPrototype.h

@@ -26,11 +26,11 @@
 
 #pragma once
 
-#include <LibJS/Runtime/Object.h>
+#include <LibJS/Runtime/StringObject.h>
 
 namespace JS {
 
-class StringPrototype final : public Object {
+class StringPrototype final : public StringObject {
 public:
     StringPrototype();
     virtual ~StringPrototype() override;

Libraries/LibJS/Tests/Number.prototype.js

@@ -0,0 +1,8 @@
+try {
+  assert(typeof Number.prototype === "object");
+  assert(Number.prototype.valueOf() === 0);
+
+  console.log("PASS");
+} catch (err) {
+  console.log("FAIL: " + err);
+}

Libraries/LibJS/Tests/String.prototype.js

@@ -0,0 +1,8 @@
+try {
+  assert(typeof Object.getPrototypeOf("") === "object");
+  assert(Object.getPrototypeOf("").valueOf() === '');
+
+  console.log("PASS");
+} catch (err) {
+  console.log("FAIL: " + err);
+}